PACE Emerging Market Vehicle Suspension Design University of Cincinnati

Suspension Team Undergraduate Students: Adam Quintana Elena Sabatini Michael Martin Nicholas Schira Graduate Assistant: Ronnie Mathew Faculty Advisor: Dr. Sam Anand

Front Suspension McPherson Strut

Dimensions of the Front Suspension Side View Bottom View

Rear Suspension Watts Linkage

Dimensions of the Rear Suspension Front View Top View Side View

Values of spring and damper constants Front spring stiffness of 16 N/mm Damping coefficient of 30 N-s/mm Rear spring stiffness of 18.7 N/mm Damping coefficient of 30 N-s/mm

Suspension Incorporated in Frame

Static FEM analysis – ANSYS Workbench Front suspension mesh Max Stress – Steering Force

Rear suspension meshMax Stress – Force from a bump Static FEM analysis – ANSYS Workbench

Loading condition –Braking Torque –Maximum steering force –Forces on suspensions while running over a bump Results –Reduced angle and increased thickness steering arm on the knuckle. –Reduced thickness of the wishbone arms. –Shortened length of pivot arms of the rear suspension. Static FEM analysis – ANSYS Workbench

Convergence Test Multiple iterations were performed on the models while increasing the number of elements in the mesh. Stresses were all converging – hence model is accurate.

Dynamic analysis – MSC ADAMS Input – Height of bump on the road –Velocity of the vehicle Output –Spring and contact forces – values used for static analysis in ANSYS

Simulation of the vehicle going over a bump on the road. Dynamic analysis – MSC ADAMS Yaw, pitch and roll orientation used to determine the resonant frequency of the vehicle. Fast Fourier Transform was performed to obtain the resonant frequency of the vehicle.

Vertical displacement of the wheel Forces ranging from 2500N to 5000N on the front and rear tires on the drivers side.

Results Front Suspension The maximum deflection of 8.22E-04 m was found during the steering simulation which was seen in the steering arm of the knuckle. A strain of 2.75E-03 was determined to be the maximum strain in the bump simulation. The highest stress came from the braking condition which was determined to be 4.48E+08 Pa. Sufficiency of Model - maximum stress was not higher than the tensile strength of the material

Rear suspension Deflection of 5.63E-04 m was determined to be the maximum deformation in the bump simulation. The highest strain came from the braking condition which was determined to be 3.02E-03. The maximum stress of 6.03E+08 Pa was found during the braking simulation. Dynamic Analysis The resonant frequency of the vehicle is Hz. Verifies stability of vehicle with values of spring stiffness and damping coefficient for both suspensions. Results

Thank You !